Electric temperature-indicator.



No. 682,084. Patented Sept. 3, I91". F. L. JOBSON.

ELECTRIC TEMPERATURE INDICATOR.

(Application filed Aug. 15, 1900.)

(No Model.)

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wlmss ks N UNITED STATES PATENT OFFICE.

FRANK LEE JOBSON, OF RICHMOND, VIRGINIA.

ELECTRIC TEMPERATURE-INDICATOR.

SPECIFICATION forming part of Letters Patent No. 682,084, datedSeptember 3, 1901.

Application filed August 15, 1900. Serial No. 26,963. this model.)

To all whom it may concern:

Be it known that I, FRANK LEE JOBSON, of Richmond, in the county ofHenrico and State of Virginia, have invented a new and usefulImprovement in Electric Temperature-indicators, of which the followingis a specitica' tion.

The object of my invention is to enable persons stationed in rooms orlocations remote or apart from rooms or locations in which a thermometeris placed to read the state of said thermometer from a distance withouthaving to visit or inspect the thermometer itself.

It is specially designed for the use of engineers and others who havecharge of the regulation of temperature in cold-storage rooms, on boardships, or elsewhere and for regulating temperature in hospitals,nurseries, hot houses, school-buildings, hotels, and other public andprivate buildings from a central point and without having to visit thevarious rooms in order to ascertain the temperature thereof.

My invention consists in the special construction and arrangement of athermometertube with terminal contacts fused in the same in exposedrelation to the mercury column, a special form of graduated resistancesconnected with said terminals, and a special form of case for inclosingthe same, the whole being adapted for use in combination with a currentmeter or indicator for indicating the height of the mercury column, ashereinafter described.

Figure 1 is a side view of the entire apparatus. Fig. 2 is a rear viewof the thermometer, and Fig. 3 a cross-section through the same on line3 3 of Fig. 1.

In the drawings, A represents a thermometer-frame, and B its glassmercury-tube, having at its lower end a bulb b. Along the tube B atregular intervals are arranged little platinum-wire contact-points 0,one opposite each graduation of the thermometer. These contacts arefused or otherwise fixed in the glass tube, so that their inner endswill be flush with and in direct contact with the mercury column asitrises and falls. Each one of these wires is a terminal of arheostat-coil, of which there are two series arranged vertically onopposite sides of the mercury-tube, each coil being composed of asuitable number of turns of insulated wire earound two pins d (l, fixedin Iheback of the frame, as seen in Fig. The shanks of these pins wherethe coils contact with them are covered by insulatingsleeves, and thewire of one coil extends to the next one above and below it in the usualmanner of rheostats. The coils are arranged in two series forconvenience in location to get close readings, and the wires 0 c' ofboth series at the top connect with the same binding-post X. Fromanother binding-post Y besides the first a wire a leads to themercury-bulb Z) and is sealed in the same or in its neck, so as to be inpermanent contact with the mercury therein. To the two binding-posts Xand Y are connected the two circuit-wires O and D, that lead from thethermometer to any remote point where the read ings are to be observedand at which point is located the indicator F, whose graduations aredesigned to correspond exactly with those of the thermometer and thedeflection of whose index-hand over the circular graduations indicatesthe elevation of the mercury column in the thermometer, and consequentlythe temperature. The indicator F may be constructed on the plan of anygood volt-meter, ammeter, or any instrument for measuring current, andwhich being well known and forming no special feature of novelty neednot be further described. Nowcurrent being established on the circuitwires 0 and D through abattery E it will be seen that when the mercurycolumn rises or falls in the tube B it cuts in or out anexactly-regulated amount of resistance in the shape of the coils e, andby a corresponding current measurement in the indicator F denotes theheight of the mercury column and the temperature of the room in which itis located. The normal condition of the circuit is open, and it isarranged to be closed at will to indicate the temperature by means ofany suitable switch or push-button, (shown at P.)

I am aware that electric temperature-indicators are not broadly new,andtherefore claim only my novel construction and arrangement of apparatusfor this purpose.

The chief distinguishing features of my invention are the particularform and relation of the resistances to the mercury-tube and thecontainingcase, the resistances being composed of Wire wound in the formof bobbins arranged transversely to the mercurytube upon pins projectingfrom the rear of the face-plate A of the case and arranged in twovertical series upon opposite sides of the tube, said face-plate havingrearwardly-projecting side strips or flanges for inclosing and housingbetween them the resistances and their connection, thus protecting themand adapting them to be inclosed by a back board or filling of cement,if desired.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In an electric temperature-indicator, the combination of a face-platehaving along its side edges two rearwardly-proj-ecting strips orflanges, a glass mercury-tube arranged in the face-plate and havingterminal wire coutacts fused therein along the line of the mercurycolumn and in exposed relation thereto, two series of resistancesconnected to said terminal contacts, said resistances being composed oftransverse wire bobbins wound upon pairs of pins projecting rearwardlyfrom the face-plate, said resistances and their connections being housedand protected Within the inclosure of the side strips, or flangessubstantially as and for the purpose described.

2. An electric temperature-indicator, consisting of a face-plate havingalong its side edges two rearwardly projecting strips or flanges, aglass mercury-tube arranged in the face-plate and having terminal wirecontacts fused therein along the line of the mercury column and inexposed'relation thereto, two series of resistances connected to saidterminal contacts, said resistances being composed of transverse wirebobbins wound upon pairs of pins projecting rearwardly from thefaceplate within the inclosure of the side strips or flanges of theframe, a binding-post connected to the mercury-bulb, and anotherbinding-post connected to the two series of resistances, and a battery,current-indicator, and electric circuit connecting the same to thebinding-posts substantially as and for the I purpose described.

' FRANK LEE JOBSON. Witnesses:

RUSSELL BARGAMIN, E. O. FoLKEs.

